Inkjet printers and related inkjet devices have proven to be reliable, efficient, and generally cost effective means for the accurate delivery of precisely controlled amounts of ink and other related liquid materials onto various substrates such as, but not limited to, glass, paper, cloth, transparencies and related polymer films. For example, modern inkjet printers for consumer market digital printing on paper offer printing resolutions in excess of 2400 dots per inch (DPI), provide printing speeds greater than 20-30 sheets per minute, and deliver individual droplets of ink in a ‘drop-on-demand’ method that are often measured in picoliters. The relatively low costs, high print quality and generally vivid color output provided by these modern inkjet printers has made these printers the most common digital printer in the consumer market. Currently, in addition to the consumer market, there is considerable interest in employing inkjet printing for high-speed commercial and industrial applications.
In general, inkjet printheads used for drop-on-demand inkjet printers and related inkjet printing systems may employ one of at least two technologies for ejecting droplets of ink. A first of these technologies employs a piezoelectric effect or a piezoelectric-based ejector element to eject the droplets from the printhead. The second of these technologies, often referred to as thermal inkjet printing, employs localized heat produced by the ejector element to vaporize a portion of the ink. A bubble produced by the vaporization expands to eject a remaining portion of the ink from the inkjet printhead as the droplet.
A limiting factor in the operation of inkjet printers is often a refill time of a bubble expansion chamber of the inkjet printhead. The refill time is particular problem when viscous inks are employed. Refill time directly and adversely impacts a firing rate or frequency of the inkjet printer.
Certain embodiments of the present invention have other features that are one of in addition to and in lieu of the features illustrated in the above-referenced figures. These and other features of the invention are detailed below with reference to the preceding drawings.